The present invention relates to a weather strip formed by joining two sealing bodies, a weather strip joining die set for forming the weather strip, and a method for manufacturing the weather strip.
Typically, weather strips are attached to the openings of the doors and the trunk of automobiles. When an opening is closed with a door or a trunk lid, the weather strip seals the clearance between the door or the trunk lid and the opening to restrict intrusion of rain water and wind into the interior.
A weather strip includes a first sealing body, which extends linearly or along an arc of a large radius of curvature, and a second sealing body, which is at a part where the extending direction changes sharply, such as a corner. The first sealing body is formed by extrusion, and the second sealing body is formed by molding. The weather strip is formed by joining these sealing bodies. Some other types of weather strips are formed by joining extruded sealing bodies.
Conventionally, the splicing has been known as a method for joining two or more sealing bodies to each other (for example, Japanese Laid-Open Patent Publication No. 2001-171441). Specifically, two sealing bodies are each fixed to a die. Then, a joining sheet, which is made of a resin material such as a synthetic rubber or a thermoplastic resin, is held between the dies, that is, between the opposed end faces of the two sealing bodies. In this state, the end faces of the sealing bodies and the surrounding parts are heated. This melts the joining sheet, so that the sealing bodies are joined to form an integral body. The excess of the molten joining sheet is cut off and removed by the two dies when the dies are abutted against each other.
A weather strip with a joined part receives a concentrated stress at the joined part when the weather strip is bent. Thus, in such a weather strip, cracks may start forming in the joined part.